Bag forming and sealing machine



July 3, 1951 F. J. PANCRATZ BAG FORMING AND SEALING MACHINE 3 Sheets-Sheet 1 Filed May 12, 1947 x t :l,

FIG. 2

INVENTOR: FRAN K J. PANCRATZ fifg/j ATTORNEYS.

y 3, 1951 F. J. PANCRATZ BAG FORMING AND SEALING MACHINE 3 Sheets-Sheet 2 Filed May 12, 1947 FlG.6

BYWZ%M,

ATTORNEYS.

y 3, 1951 F. J. PANCRATZ 2,559,368

BAG FORMING AND SEALING MACHINE Filed May 12, 1947 5 Sheets-Sheet 5 l I I INVENTORI FRANK J. PANCRATZ ATTORNEYS.

Patented July 3, 1951 UNITED STATES PATENT OFFICE BAG FORMING AND SEALING MACHINE Frank J. Pancratz, Park Ridge, Ill.

Application May 12, 1947, Serial No. 747,459

12 Claims.

1 My invention relates to bags in which groceries such as coffee, peas, raisins, etc. are packed, and

more particularly to means for procuring a vacuum closure for such bags in order to preserve the contents thereof. Machines have been devised which accomplish this purpose, but such machines as have come to my attention are large and intricate and therefore expensive to build and maintain. It is therefore one object of the present invention to provide a machine which is compact and operable by hand or power means.

A further object is to design the novel machine with a minimum number of parts consistent with proper operation.

Another object is to include operative means in the novel machine which follow well established mechanical principles.

An important object is to provide a machine of the above character which is easy of access and 'simple to operate.

With the above objects in view, and any others which may suggest themselves from the description to follow, a better understanding of the invention may be had by reference to the accompanying drawings, in which Fig. 1 is a side elevation of the machine as designed for manual operation;

Fig. 2 is a top plan View;

Fig. 3 is an enlarged section on the line 33 of Fig. 2;

Fig. 4 is a section on the line 4--4 of Fig. 3;

Fig. 5 is a section on the line 55 of Fig. 4;

Fig. 6 is an enlarged section on the line 66 of Fig. 4; and

Fig. '7 is an enlarged section of a detail which occurs in the upper left and right hand portions of Fig. 4.

In accordance with the foregoing, specific reference to the drawings indicates the base of the novel machine at [5. Figs. 1 and 2 show that the base can be secured by bolts H5 or other suitable means to a table l1 in a :manner to project the greater portion of the machine into a space where the bags are handled. It is intended that such space accommodate the bags after they are filled, so that they may be taken one by one and inserted into the present machine for the vacuum closing operations.

Accordingly, the forward portion of the base l5 carries a pendent frame IS on the forward side of which is mounted a rectangular forming box 20. As indicated in Fig. 4, this box is suitable for receiving the lower portion of a paper bag 2|. This type of bag is made of heavy or double-ply wax paper; or, it may be made laminated of metal 2 foil and treated paper. The form of the bag is standard, but for the present treatment its upper portion or mouth 22 is flattened so as to become considerably wider, as suggested in Fig. 4.

The mouth of the bag 22 is designed to receive a plunger 25 of wedge form, the plunger being of diamond shape in horizontal section, as indicated in Fig. 6, and thinned out to sharp edges at the sides, whereby to fit hermetically in the mouth of the bag when the latter is pressed to the fiat form shown. The plunger is vertically bored with a series of passages 21, these communicatin at their upper ends with a crossduct 28 which opens at one end of the plunger. Here the duct may receive a hose 29 leading to a suitable vacuum unit (not shown). Thus, with the vacuum unit in operation, the air and vapor over and in the goods in the bag 2| may be drawn upwardly through the plunger 25, producing a partial vacuum in the bag.

Fig. 3 shows that the mouth of the bag converges in a downward direction, making it possible for the bag to close at its neck or narrowest portion while the evacuating operation is on. To counteract this tendency, a pair of separator rods 30 are disposed in the terminal passages 21, such rods passing through the upper portion of the plunger. Fig. 7 shows that each rod 30 passes through a rubber packing 32 over the duct 28, with a nut 33 threaded into the top of the plunger to tighten the packing around the rod. Each rod rises into a bore 35 of a cross-head 31 which is positioned above the plunger 25, set screws 38 from the front serving to secure the rods in the cross-head. As indicated in Figs. 3 and 4, the lower ends of the rods are pointed; and the rods are designed to become lowered into the mouth of the bag concurrently with the plunger, and crowded through the neck of the bag to insure the slight separation of its walls.

Dotted lines in Fig. 3 show the plunger 25 at the uppermost position of its travel. The plunger is carried by a vertical bolt 40 which rises freely through the cross-head 31. The latter is supported by an arm 42; and a pair of springs 43 are interposed between the cross-head and the plunger. The base [5 has a bearing 45 for the bottom portion of a vertical shaft 46; and. a standard 41 is erected on the base l5 for the purpose of projecting a bearing 48 for the upper portion of the shaft 46. The latter receives a washer 49 over the bearing 48 and a crank handle 50 over the washer, so that the shaft is manually rotatable by means of the crank handle. The shaft 46 carries a cup-type cam 5| below the 3 bearing 48, the edge 52 of the cam being oblique, as clearly indicated in Fig. 3. The arm 42 is extended outwardly with rearward branches 53 which terminate alongside the standard 41 to be pivoted to it as indicated at 54. The rear end of the arm 42 receives a screw 55 on which a roller 56 is freely journaled, the position of the roller being over the edge 52 of the cam 5| at the front. It is now apparent that the rotation of the shaft 455 through a half-turn will; lower the assembly of the cross-head 37 and plunger 25 from the dotted line position in Fig. 3 to the full line position in the same figure.

A frontal closure is provided, .for. the. frame. IS. in the form of a wall 60. The latter is extended back at the bottom with lugs 6| forminggpiw otal connections 62 with a pair of similar lugs 63 extending from the frame l9: Thus, the closure 50 may be opened by swinging the: same from the full line position in Fig. 3 to the dotted line-position in the same figure. carries-a pair ofside walls 64. A latch-bar 65 is located in front of the closure 60at the top, terminal arms 66 of the latch-bar extending rearwardly alongside the walls 64 to attach with pivotal connections. 61 thereto. The latch-bar 65 is extended forwardly with a knob 68. When the forward portions of the arms '66 rest on the closure 6|] as indicated'in Fig. 3, the latch-bar, 55' overhangs the closure in front, preventing the same from being opened. However, when the knob 68 is raised, the closure becomes released, and a handle 69 projecting from the front of the closure 66' may be used to draw the same open as previously explained.

The closure 60 has secured to it by means of screws 10 a vertical series of anvil bars Tl, l2 and 13. The bars H and 13 are plain, but the bar l2z-is fitted with a projecting rubber pad 14. The bars H, 13 and the pad 14 are directed toward the frontal side of the bag mouth 22; and a,set of companion bars 15,-,16, and I! aredi- Thev base l5 rected toward the bag from the rear, these serving-as pressure bars. Thus, the bars 75 and ll are, plain, but fitted'with electric heating units 78; while thebar. 16 I is fitted with a rubber pad l9 similarto thepad 74. It is-noted that the contiguous faces of these pads are inclined similarly to the Walls of the bag mouth. Also, the plunger 25'is formed witha, series of horizontal.

grooves 80 substantially opposite the pads i land-19.

It is intended that the pad v 19 advance toward the pad I4when the plunger 251s lodged; in the mouth of the bag as shown in Fig. 3, whereby to firmly press such .mouth-into engagementwith Now the pressure bar TI will'advance in the direction of the anvil bar, 13; and ;compress the mouth of the bag;inthe regionabove its neck, heating the bagmaterialto the, extent where it willbecome sealed; After this operation, the

crank-handle 50 is rotated-to raise the plunger 25'. out of the'bag. Now'the -pressure bar -15 is .de--.

signed to advance in the direction of the. pressure bar H and tightly-seal th'emouth) ofi-the bag, by pressure under heat.

Fig. 3,shows that themovementof the prese.

sure bars 15, 1,6 and I1 is Controlledbyaseries 4 of cams 8|, 82 and 83 fixedly mounted on the control shaft 46. The cams act through follower rollers 84 carried by the pressure bars; and Fig. 2 shows that these are slotted at 85 to allow clearance for springs 88 normally drawing the pressure bars toward the standard 41 in order to keep the follower rollers 84 in engagement with the cams 8!, 82 and 63. It is understood that the arrangement of these cams will be such as to induce the operationsof the pressure bars in properly timed relation to the raising and lowering of the separator rods 39 and the: plunger 25.

It i understood that the deposit of the bag 2! into the machine occurs while the plunger 25 is inzthe fully .raised position. Thus, the out-swing ofthe frontal closure G0 carries the anvil bars H, 12 and 13' to a-remote position, leaving ample roomfor the deposit of the bag into the forming box 20. The top ofithe same has a fiange 96.: directed toward the neck of the bag from the rear; and the closure Bilalso carries-a flange 9i companion to the flange 90 by being directed;

toward the neck of the bag from the front. The closure 6!) also carries a pressure plate 92 by means of-a slidable screw 92a, the plate being pressed in rearwarddirection by upper and lower springs 93 partly encased in cavities M made in the:ba,ok: side. of the closure 60. Thus, on the application, ofthe latter, the pressure plate 92 servesto hold the bagin place andpress it into. even shape.

Itis desirablethat the mouth of the bag be drawn flat between its side edges in order that itmay closely'line the plunger after the latter descends into the mouth of the bag. Ordinarily, the upper position of the plunger is such that its bottom end isslightly lower-than the height of the bag. into the machine, its mouth is trained with an upward turn to receive the bottom of the plunger before the bag is set down on the bottom of the formingbox 2B. Finely dotted lines in Fig. 3-

show. the upper position of the cross-head 3'? and the plunger 25. Fig;.; 4-shows more clearly that. arpair of outwardly. directed links 95 ex tend from each side ofthecross-head, each pair" of links connecting withavertical arm 96; Finely dotted linesin the same; figure indicate that when the cross-head 31 is up, the links- 95 are.

inclined and, the: arms- 96 gathered until the lower'links rest .on brackets 91 extended from the bottom ofthe cross-head. The lower ends of the arms 96 are rounded, as indicated-at 9B, and'leave-ample clearance for the insertion of the-bag. The arms 96 have outward fingers 99 resting on the inner arms I50 of bellcranks I0! journaled in the walls 64.v Now, in the event that the plunger 25 is'lowered, the stationary.

position of. the-fingers 99 on:-the arms lfiilwill force: the 1 arms 96:; to separate, to the positions.

shown by full lines in Fig. ,4, causing .themouth tension; I02.;of each bellgcrankglever l0], such.

extension receiving ;a screw I llilithrough its lowerend; The screwzpasses through an opening H14. in the .;wall 64 to thread. into. the pressure. plate l pr ssure .:p1-ate:advanc.es,-.the& bell. crank lever I01 Therefore,- when the bag is inserted is caused to rock in a counter-clockwise direc-' tion when viewed in Fig. 1, so that its arm I00 will raise the arm 96 clear of the bag. The plunger also carries a heating unit I05.

It will now be apparent that the novel machine procures the sequence of exhausting, pressing and sealing operations in respect to the mouth of the bag by means of a series of simple instrumentalities. These are all operated from a basic control shaft with a timing factor designed to harmonize the operations automatically as the crank handle 50 is turned. Thus, the bag is treated by machine methods which are easily controllable by hand. Further, the devices entering into the treatment of the bag are separable for quick access to any of them in case of adjustment or repair, and for open access to insert the bag. The frontal closure carries parts of the mechanism directly applicable to the bag,

applying such parts and flattening pressure to the bag by the simple return of the closure to its normal position. All the factors entering in the mechanism are compactly grouped to render the machine small enough to be mounted as a unit or attachment on any table or support in the vicinity of the bag filling area. Finally, the machine accomplishes an efficient operation by means of relatively few and simple parts.

While I have described the invention along specific lines, various minor changes or refinements may be made therein without departing from its principle, and I reserve the right to employ all such changes and refinements as may come within the scope and spirit of the appended claims.

I claim:

1. Means for closing a paper bag whose mouth is formed with closely spaced Walls joined by side folds, comprising a substantially flat plunger adapted to be lowered between said walls and spaced from said side folds, the plunger tapering to sharp edges at the sides, and means outside of said walls to press them against the plunger and against each other beyond said edges, whereby to constitute the plunger a hermetical closure for said mouth, wherein said walls converge in downward direction to form a neck for the bag, the plunger being tapered in; downward direction to conform with the gather of said walls, a vertically-reciprocable support, and a series of rods depending from the latter and adapted to be lowered into said neck to separate the walls thereof on the downstroke of the support, said rodspassing through the plunger.

2. Means for closing a paper bag whose mouth is formed with closely spaced walls joined by side folds, comprising a substantially flat plunger adapted to be lowered between said walls and spaced from said side folds, the plunger tapering to sharp edges at the sides, and means outside of said walls to press them against the plunger and against each other beyond said edges, whereby to constitute the plunger a hermetical closure for said mouth, wherein said Walls converge in downward direction to form a neck for the bag, the plunger being tapered in downward direction to conform with the gather of said walls, a vertically-reciprocable support, the plunger being suspended from the support with allowance for lost upward motion, and a series of rods depending from the support and adapted to be lowered into said neck to separate the walls thereof on the downstroke of the support, said rods passing through the plunger, and the latter remaining in said mouth by virtue of said lost motion by to constitute the plunger a hermetical clo--v sure for said mouth, wherein said walls converge in downward direction to form a neck for the bag, the plunger being tapered in downward direction to conform with the gather of said Walls, a vertically-reciprocable support, the plunger being suspended from the support with allowance for lost upward motion, a series of rods depending from the support and adapted to be lowered into said neck to separate the walls thereof on the downstroke of the support, said rods passing through the plunger, the latter remaining in said mouth by virtue of said lost motion on the upstroke of said support, whereby to raise the rods out of said neck before the plunger is raised out of said mouth, and yieldable means interposed between the support and the plunger.

4. Means for closing a paper bag whose mouth is formed with closely spaced walls joined by side folds, comprising a substantially fiat plunger adapted to be lowered between said walls and spaced from said side folds, the plunger tapering to sharp edges at the sides, thin arms entering the mouth of the bag between the plunger and said folds, means separating said arms to fit in said folds and draw the mouth of the bag.

to maximum width, and means outside of said walls to press them against the plunger and against each other beyond said edges, whereby to constitute the plunger a hermetical closure for said mouth.

5. Means for closing a paper bag whose mouth is formed with closely spaced walls joined by side folds, comprising a substantially flat plunger adapted to be lowered between said walls and spaced from said side folds, the plunger tapering to sharp edges at the sides, thin arms entering the mouth of the bag between the plunger and said folds, means separating said arms to fit in said folds and draw the mouth of the bag to maximum width, means outside of said walls to press them against the plunger and against each other beyond said edges, whereby to constitute the plunger a hermetical closure for said mouth, and. a connection between said plunger pressing means and said arm separating means to apply the latter before the plunger pressing means.

6. Means for drawing the mouth of a flexible bag having side folds to maximum width comprising a medial overhead support, auxiliary side supports, a pair of vertical arms near opposite sides of the medial support and depending into the mouth of the bag, said arms having outward branches resting on said side supports, inclined parallel links extending from the overhead support to the related arms, and means to lower said support and swing said links to horizontal positions, whereby to separate said arms-with their branches sliding on the related side supports and cause the arms to engage said folds with pressure.

7. Means for exhausting and sealing a bag r: who'se mouth-has a fusible property and is formed with closely spaced walls, comprising a plunger designed to be partly advanced into said mouth to fitbetween said walls, the plunger having means to establish communication between the bag and an exhausting medium, first. means for pressing the medial portions of said walls against the plunger to form a hermetical closure between the same and said portions preparatory to the exhausting action, heat-pressure means applicable to the inner portions of said walls after said action to'seal such inner portions together, second means for releasing said first means, meansfor withdrawing the plunger from said mouth in such event, said pressing and heat-pressure means having grouped lateral extensions, a support for the latter, a rotatable shaft carried by the support crosswise of. the extensions, and a series of cams carried b-y the shaft opposite/the extensions and designed tooperate the same as followers to apply said;pressing and heat-pressure means as stated.

8'. Mean for exhausting and sealing a .bag.

whose mouth has a fusible property and is formed.

with-closely spaced walls, comprising a plunger designed to be partly advanced into said mouth. to fit between said walls, the plunger having means to establish communication .between the bag and an exhausting medium, first'means for pressing the medial portions of said walls against the plunger to form a hermetical closure between the same and said portions preparatory to. the exhausting action, heat-pressure means applicable to the inner portions of said*'walls after said. action to seal such inner portions together, sec-- ond means .for releasing said first means, means for Withdrawing the plunger from said mouth in.

such event, wherein the bag. is in upstanding position and the path of the plunger vertical, said means for withdrawing the plunger comprising a support, a vertical. shaft rotatable in the same, a carrier. for the. plunger formed as a follower, and a cam carried by the shaft and. efiective on:

the partial rotation of the shaft to withdraw the plunger by raising said follower and. carrier;

9. Means for exhausting and. sealing .a bag;

amsascs 8'1 bleto the irmerportions of said walls: after said action'to seal such inner portions together, second means for-releasing said first means, means for withdrawing the plunger from said mouthinsuch event, wherein the bag is in upstanding position'and the path of the plunger vertical, said means for withdrawing the plunger comprising a-support, a vertical shaft rotatable in the'same', a-carrier for the plunger formed as a-follower, and; a cam carried by't'he shaft and effective-on the partial rotation of the shaft to Withdraw the plunger'by raising said follower and carrier,:said cam. being a ring-shaped member with its top-endi in an oblique plane, an'd saidfollower riding on said top end. I 10. Means for exhausting and sealing a bag whose mouth has a fusible property and is; formed with closely spaced walls, including aplungerad'apted to be advanced into said mouthto fit between said walls, two series 0f coopera-rti-ve elements applied from the exterior of saidwalls to press them against the plunger and seal. the walls together in aprescribed order, a stationary support for the bag and the series --.of elements on one side of the bag, and a carrier forthe series of elements on theother side thereof,said carrier being movablerelative to the support to leave a clearance for: themounting ofsthe' bag on and the removal of the same iromssaid support.

11. The structure of claim 10, said. carrier being pivoted to the support at a point opposite the bottom of thebag to swing toward and from the related side of the bag.

12. The structure of claim 10, said carrier."

being pivoted to the support at a point opposite the bottom of the bag 'to swing'toward and. from the related side of the bag, the support having a flat backing -for the. opposite side-of the bag,

and yieldable pressure means mounted on.

inner side of said carrier for pressing saidirelated;

side of the bag flat to render the bag rand -its;

contents compact.

FRANK J. PANCRATZ.

REFERENCES GITED' The following references are-0f record in the file of this patent:

UNITED STATES PATENTS.

Van Antwerpen Feb. .7, .1958; 

